Egg Safety and Quality Research Unit, USDA Agricultural Research Service, Athens, GA 30605, USA.
Poult Sci. 2011 Sep;90(9):2063-8. doi: 10.3382/ps.2010-01139.
Eggs from alternative production practices are a growing niche in the market. Meeting consumer requests for greater diversity in retail egg options has resulted in some unique challenges such as understanding the food safety implications of eggs from alternative production practices. A study was conducted to determine what, if any, differences exist between nest run conventional cage-produced eggs and free range-produced eggs. A sister flock of brown egg layers was maintained in conventional cage and free-range production with egg and environmental sampling every 6 wk from 20 to 79 wk of age. Aerobic, coliform, and yeast and mold populations were monitored. Environmental microbial levels were not always indicative of egg contamination levels. When significant differences (P < 0.05 and P < 0.0001, dependent on season) were observed among treatments for coliforms, shell contamination levels of free-range nest box eggs and free-range floor eggs were always greater than those of conventional cage eggs, which remained low throughout the study (0.42-0.02 log cfu/mL). Shell yeast and mold levels were significantly greater in free-range floor eggs than in free-range nest box eggs and conventional cage eggs throughout the entire study. Egg contents contamination levels were extremely low for all monitored populations and treatments. Season of the year played a role in both environmental and egg microbial levels. Winter had the lowest levels of all populations monitored for all treatments, except for aerobic free-range floor egg shell emulsions, which were increased (3.6 log cfu/mL). Understanding the differences in microbial populations present on conventional cage-produced and free range-produced eggs can lead to the development of effective cleaning procedures, enhancing food safety.
替代生产实践的鸡蛋在市场中占据越来越大的份额。为满足消费者对零售鸡蛋品种多样化的需求，出现了一些独特的挑战，例如了解替代生产实践生产的鸡蛋的食品安全影响。进行了一项研究，以确定传统笼养产蛋鸡和散养产蛋鸡的鸡蛋之间是否存在差异。在传统笼养和散养生产中饲养了一组棕色蛋鸡，从 20 至 79 周龄每隔 6 周进行鸡蛋和环境采样。监测了需氧菌、大肠菌群、酵母和霉菌数量。环境微生物水平并不总是表明鸡蛋污染水平。当在不同处理组中观察到大肠菌群存在显著差异（P<0.05 和 P<0.0001，取决于季节）时，散养巢箱蛋和散养地面蛋的蛋壳污染水平始终高于传统笼养蛋，整个研究过程中传统笼养蛋的污染水平一直较低（0.42-0.02 log cfu/mL）。在整个研究过程中，散养地面蛋的蛋壳酵母和霉菌水平始终高于散养巢箱蛋和传统笼养蛋。所有监测的种群和处理组的蛋内容物污染水平都极低。一年中的季节对环境和鸡蛋微生物水平都有影响。除了有氧散养地面蛋的蛋壳乳液增加（3.6 log cfu/mL）外，冬季所有处理组监测到的所有种群水平都最低。了解传统笼养产蛋鸡和散养产蛋鸡中存在的微生物种群差异可以促进制定有效的清洁程序，提高食品安全。
